摘要
在20℃至-55℃下对16MnR材料进行Charpy冲击试验,用声发射技术监测各温度下冲击开裂的过程。采用小波分析结合傅里叶变换的方法,得到了16MnR试样开裂过程的波形频谱特性及电压幅值,并且采用金相和SEM对冲击断口进行了组织、形貌分析。结果表明:随着温度的下降,声发射计数率、声发射能量及声发射持续时间均呈降低趋势,声信号幅值变化不大。小波分解后的d2层能量包含冲击断裂的主要能量,与冲击功的变化趋势相似,具有较强的相关性。试验结果为声发射技术监测冲击载荷作用下的材料内部结构演化提供了一个思路。
Charpy impact test of 16MnR was carried out in 20 ℃ ～-55 ℃,the fracture process was detected by acoustic emission technology,and the impact fracture was analyzed by metallography and SEM.The results showed that the AE count rate,energy and duration showed decreasing trend when temperature decreased,but amplitude changed little.The d2 energy of wavelet decomposition contained the mainly impact crack energy,and the same trend was found with impact energy.In this text,wavelet analysis and Fourier transform are used to ensure the spectrum characteristics and voltage value generated in crack of 16MnR samples,and thus providing a way for quantitative detecting internal structure change of material under impact load.
出处
《无损检测》
2014年第1期54-57,共4页
Nondestructive Testing
关键词
声发射
冲击
小波分析
傅里叶变换
能量系数
Acoustic emission
Impact
Wavelet analysis
Fourier transform
Energy coefficient
